Use of Compatible Polymer Blends To Fabricate Arrays of Carbon Black−Polymer Composite Vapor Detectors

Abstract

Compatible blends of poly(vinyl acetate) and poly(methyl methacrylate) have been used to produce a series of electrically conducting carbon black composites whose resistance is sensitive to the nature and concentration of an analyte in the vapor phase. The dc electrical resistance response of the composites was found to be a nonlinear function of the mole fraction of poly(vinyl acetate) in the blend. These compatible blend composite detectors provided additional analyte discrimination information relative to a reference detector array that only contained composites formed using the pure polymer phases. The added discrimination power provided by the compatible blend detectors, and thus the added diversity of the enhanced detector array, was quantified through use of a statistical metric to assess the performance of detector arrays in various vapor classification tasks.

Combinatorial Approaches to the Synthesis of Vapor Detector Arrays for Use in an Electronic Nose

“…A potential drawback is the possibility that the response of the block copolymers could be a linear combination of the two homopolymers, thus yielding no unique sorption data that could be used to identify analytes. 18 Block copolymers were synthesized using the living polymerization process of ring-opening metathesis polymerization, as depicted in Scheme 1. 19 The monomers were chosen such that one monomer was very polar and the other monomer was relatively nonpolar, to maximize the difference in the sorption coefficient of the pure homopolymers in the presence of a range of analytes.…”

Exploitation of spatiotemporal information and geometric optimization of signal/noise performance using arrays of carbon black-polymer composite vapor detectors

“…An automated flow system was used to deliver pulses of a diluted stream of solvent vapor to the detectors [14]. The carrier gas was oil-free air obtained from the house compressed air source (1:10 AE 0:15 parts per thousand (ppth) of water vapor) controlled with a 28 ml min À1 or a 625 ml min À1 mass flow controller (UNIT).…”

“…In most studies to date, the detectors in such an array are placed in nominally spatially equivalent positions relative to the analyte flow path [1,11,14]. In such a configuration, any spatiotemporal differences between detectors are minimized, and the array response pattern is determined by the differing physicochemical responses of the various detectors towards the analyte of interest.…”

Integrated chemical sensors based on carbon black and polymer films using a standard CMOS process and post-processing

“…We are currently combining this technology with the large number of chemically selective polymer sensors available [3] to create large arrays of chemically diverse sensors capable of chemical classification. We are also investigating more advanced circuitry for each sensor site, such as gain, adaptation of baseline drift, and ratiometric sensing.…”

“…The sensors are based on the conducting polymer approach of Lewis et al [2][3][4][5], employing carbon black and non-conducting polymers. Carbon black particles mixed with the polymer, as opposed to polymerization, create a conducting polymer film.…”